September 21, 2010 |
The dark dust thrown up by human activity in the deserts of the Southwest hastens the melting of Rocky Mountain snow and ultimately reduces the amount of water flowing into the upper Colorado River by about 5%, scientists reported Monday. The lost water amounts to more than 250 billion gallons — enough to supply the Los Angeles region for 18 months, said study leader Thomas H. Painter, a snow hydrologist at the Jet Propulsion Laboratory in La Cañada Flintridge. "That's a lot of water," said Painter, whose study was published online by the Proceedings of the National Academy of Sciences.
July 24, 2012 |
Do polar bears face obliteration as a species, not from starvation as the northern ice melts but through interbreeding with brown bears as changes in the climate bring them into contact with each other? Authors of a new report say that's a distinct possibility. The closest relative of the polar bear is the brown bear - matings between grizzlies and polar bears sometimes happen in zoos or the wild, yielding very rare examples of hybrids known as grolar bears or pizzlies. Webb Miller of Pennsylvania State University and colleagues set out to examine the timing of the divergence between the two species, using a whole mess of DNA data - from contemporary brown bears, polar bears and black bears as well as from a polar bear that lived 110,000 to 130,000 years ago. (The ancient DNA was obtained from a jawbone found in Norway.)
April 3, 2013 |
Let that long-held breath out, folks. The Alpha Magnetic Spectrometer has picked up a lot of mysterious antimatter in low Earth orbit - but that doesn't necessarily mean it's a sign of dark matter. In fact, even with the 400,000 positrons picked up by the cosmic-ray experiment -- the largest number of such particles ever analyzed in space -- it's unclear whether those positrons result from decaying dark matter, or simply from pulsars sending particles into the universe. "What you have probably seen from the data is a significant new measurement," said Brown University physicist Richard Gaitskell, a lead scientist on a different dark matter detector called the Large Underground Xenon experiment.
March 20, 2013 |
Ladies and gentlemen, the Voyager 1 spacecraft has left the solar system - or has it? Scientists are continuing to debate whether the lonesome craft has finally escaped the solar system after 35 years of travel or has simply entered a previously unknown region of solar influence. On Wednesday, a study published in Geophysical Research Letters , a journal of the American Geophysical Union, suggests that the Voyager spacecraft exited the heliosphere - that region of space dominated by solar winds and long considered to be the edge of the solar system - on Aug. 25, 2012.
October 17, 2009 |
Is 2012 the end of the world? If you scan the Internet or believe the marketing campaign behind the movie "2012," scheduled for release in November, you might be forgiven for thinking so. Dozens of books and fake science websites are prophesying the arrival of doomsday that year, by means of a rogue planet colliding with the Earth or some other cataclysmic event. Normally, scientists regard Internet hysteria with nothing more than a raised eyebrow and a shake of the head. But a few scientists have become so concerned at the level of fear they are seeing that they decided not to remain on the sidelines this time.
July 5, 2013 |
What if the solution to smog was right where the rubber meets the road? Scientists in the Netherlands have found that installing special air-purifying pavement on city streets can cut air pollution nearly in half. Researchers at Eindhoven University of Technology outfitted one block in the city of Hengelo, Netherlands, with paving blocks sprayed with titanium oxide, which has the ability to remove pollutants from the air and turn them into less harmful chemicals. The researchers left normal pavement on an adjacent street as a control.
April 1, 2014 |
Happy April Fool's Day! Why not celebrate with a little humor from the world of science? No, that's not an April Fool's joke. It really IS possible to blend humor with science and math. The American Chemical Society proves it in the video above. You may find some of the jokes funnier than others. One of my favorites: “Never trust an atom - they make up everything.” There's another gem about two glasses of water concerned about the too-cool-for-school behavior of their ice-cube son. The punch line requires a junior-high understanding of chemistry.
December 4, 2010 |
Have scientists finally discovered the genetic fountain of youth? Hardly. But by creating a genetic switch that allows them to artificially age — and rejuvenate — lab mice, scientists have shown that it is possible to reverse some effects of aging in mammals. "It indicates there's a point of return if you remove the underlying cause of the aging," said Dr. Ronald DePinho, the molecular biologist at the Dana-Farber Cancer Institute at Harvard Medical School who led the study, published online this week in the journal Nature.
January 28, 2013 |
A team of storm-chasing scientists sampling rarefied air has found a world of bacteria and fungi floating about 30,000 feet above Earth. The findings, detailed Monday in the Proceedings of the National Academy of Sciences, suggest that microbes have the potential to affect the weather. Scientists have long studied airborne bacteria, but they typically do so from the ground, often trekking to mountain peaks to examine microbes in fresh snow. Beyond that, they don't know much about the number and diversity of floating microbes, said study coauthor Athanasios Nenes, an atmospheric scientist at Georgia Tech.
December 24, 2010 |
In the supermarket, on the street and in bars, Europeans have long thought in units of 10 ? fruit is weighed by the kilo, beverages dispensed by fractions of a liter and distances marked off in meters. Most Americans, meanwhile, still think in pounds, pints, feet and miles. The metric system, or SI (short for the International System of Units, or Systeme International d'Unites in French), has roots that stretch to 1670, when French scientist and abbot Gabriel Mouton proposed a decimal system based on the circumference of the Earth.